Abstract
In order to determine the number of hearing lesions in school children caused by the noise from chinese crackers on one single Norwegian Independence Day, audiometric surveys were carried out before and after Independence Day on 791 pupils 12–15 years of age. The follow—up examinations, which included Closed—Spaced—Frequency pure tone audiometry, revealed that about 0.7% of the boys had acquired a considerable permanent hearing loss. As the dips in the audiograms caused by the impulsive noise are narrow, conventional audiometry may fail to detect the hearing loss. A modification of conventional audiometers is proposed to overcome this defect.